Communication using VLANs (Virtual Local Area Networks) has been performed. In a system that shares a network, the VLANs can divide and use the network. For example, in a system in which a plurality of communication apparatuses (hubs) are connected, by performing VLAN settings on the connection ports of the communication apparatuses (the hubs), one network in physical arrangement can be logically operated as a plurality of networks. Such a technology is disclosed in Patent Literatures 1 to 3.